1. Field
The present embodiments generally relate to a split-flow contactor for fixed bed catalysis and methods for using same.
2. Description of the Related Art
Carbon monoxide is a by-product of syngas production and other chemical processes. Carbon monoxide can be a catalyst poison or contaminant and thus, problematic for downstream processing. However, carbon monoxide is combustible, highly reactive, and potentially poisonous at certain concentrations and cannot be released to atmosphere in any significant quantities.
Processes for oxidizing carbon monoxide to carbon dioxide have been used. Such techniques are typically known as carbon monoxide shifting, and are catalytically driven (See e.g. U.S. Pat. No. 3,509,043; U.S. Pat. No. 4,313,908; U.S. Pat. No. 4,380,529; U.S. Pat. No. 5,985,231; and U.S. Pat. No. 6,692,705). As with any catalytic process, bed geometry is one critical factor in the operation and optimization of the reaction. Often, maximizing production of desired products, or conversely, minimizing the production of undesired by-products, is largely dependent upon fluid residence time.
Fluid residence time is typically based on bed volume and volumetric flowrate to the bed. Thus, maintaining a pre-determined residence time while increasing flowrates or increasing residence time at a constant flowrate usually requires a proportionate increase in bed volume. Since pressure drop through the bed is typically proportional to the bed depth, bed volume is typically increased by maintaining a constant bed depth and increasing the bed surface area for applications which are limited in pressure drop.
However, economics and space limitations often preclude increasing cross sectional area within existing vessels or within processing facilities. In such instances, bed volume is typically increased by adding depth to an existing bed or by adding additional vessels in parallel or series. Increased bed depth results in increased pressure drop through the bed which is not always desirable and in some cases, is not an option.
There is a need, therefore, for systems and methods that provide suitable residence time, minimize pressure drop, and minimize space requirements.